Appeal to nature is a fallacious argument, because the mere "naturalness" of something is unrelated to its positive or negative qualities – natural things can be bad or harmful (such as infant death and the jellyfish below), and unnatural things can be good (such as clothes, especially when you are in Siberia). Another problem is the distinction of what is "natural" and what is not, which can be murky: crude oil occurs naturally, but it's not something you'd like poured on seabirds or your garden. The word "natural" itself has no exact definition and can be used in multiple ways, thus allowing equivocation.

An excellent example of how tangled the concepts of "natural" and "non-natural", "desirable" and "undesirable" can become is the heart medication digoxin. It's a natural product of the foxglove plant (Digitalis spp.), which is quite poisonous as a plant. It is chemically extracted, or sometimes chemically synthesised, and dispensed in pill form because it relieves heart arrhythmias at therapeutic levels. However, at toxic levels it causes potentially fatal heart arrhythmias — and in fact is one of the plant toxins that makes foxglove so poisonous, and there is a fairly narrow window between therapeutic and toxic levels.[note 2] (One notable healthcare serial killer, Charles Cullen, used it as his killing agent of choice.) So is digoxin natural or non-natural? Desirable or undesirable?

“”There is a reason pharmacology abandoned whole plant extracts in favor of isolated active ingredients. The amount of active ingredient in a plant can vary with factors like the variety, the geographic location, the weather, the season, the time of harvest, soil conditions, storage conditions, and the method of preparation. Foxglove contains a mixture of digitalis-type active ingredients but it is difficult to control the dosage. The therapeutic dose of digitalis is very close to the toxic dose. Pharmacologists succeeded in preparing a synthetic version: now the dosage can be controlled, the blood levels can be measured, and an antibody is even available to reverse the drug’s effects if needed.

In other words, whereas medicinal plants contain variable and unpredictable quantities of pharmacologically active substances, drugs are precisely dosed and you always know the exact quantity of active ingredient you are getting.

Appeals to nature are often encountered in advocacy for alternative medicine, organic food, general lifestyle woo, anti-vegetarianism, as well as in anti-industrial and anti-technological rhetoric, usually exhibiting themselves as something like:

This is obviously flawed, as in the following "reasoning": Arsenic is natural, and therefore it is better for you than the unnatural (hence bad) acetaminophen in Tylenol.[note 3] Of course, very few people actually take the appeal to nature to its logical conclusion, so they instead prefer to handwave the issue of toxic plants away with some non-reason that could perhaps be satirically described as "All plants are natural. But some plants are more natural than others."

In favor of the idea that it is better to "live naturally," some note that in earlier eras, when people "lived naturally," there were fewer cases of diseases commonly associated with the modern era, such as cancer or Alzheimer's. They argue that this is because of the lack of "synthetic" disease-causing substances in those times. However, there is another, more likely, explanation. Cancer[3] and Alzheimer's are primarily diseases of old age. During the era of "natural living," people did not have particularly long lifespans, and so they did not, in general, live long enough to develop these diseases. Not to mention that many significant causes of cancer are perfectly natural, such as tobacco, alcohol, and birthwort (Aristolochia): see the Carcinogens section, below. Another common argument is that wild animals do not succumb to chronic illnesses,[4] in contrast to humans or their domesticated pets. This is not particularly convincing either, as this quote from Quackwatch illustrates:

“”For example, [Harvey Diamond] claims that "animals in nature are magnificently healthy in comparison to the health that we humans experience" but that pets and zoo animals develop "many of the problems of humans." The fact is that most animals in nature are infested with parasites and succumb to infections and malnutrition. It is only because predators usually kill sick animals that we don't see them stumbling across the plains and through the jungles. Perhaps it has never occurred to Harvey Diamond that the average American lives much longer than any mammal in the wild. The reason pets and zoo animals develop debilitating diseases is because they live much longer than their wild "cousins."[5]

This is pure, delicious 100% natural raspberry ketone, fresh from the plant!! Mmmmm...

This is toxic, synthetic p-Hydroxybenzyl acetone, a horrible pharmaceutical super-poison. You say you can't tell the difference? That's just because you're just too close-minded.

Alternative medicine's obsession with "naturalness" can lead to some amusing incidents. One herb company chemically tested synthetic and natural raspberry ketones to determine whether it was possible to distinguish between the two.[6] They couldn't find any difference. Rather than conclude the synthetic and natural molecules were exactly the same, they decided not to sell the product at all, just in case.[6]

This is one example of the common belief that molecules come in two forms: the ones found in plants, which are "natural" and hence safe, and "synthetic" ones, which are always inferior to and more dangerous than "natural" ones.

However, if, as the appeal to nature posits, synthetic substances were lethal, and natural ones were perfectly safe (or at least much less harmful), then the differences between these alleged types of molecules would be enormous, and it would be the easiest thing in the world to distinguish between them. The fact that this is clearly not the case (as the previous example shows) strongly indicates that this supposed distinction does not actually exist.

Such a belief also assumes that there is some method by which a "natural" molecule can be turned into its synthetic counterpart (for instance, "natural" water into "synthetic" water). That is, there should be an experimentally demonstrable sequence of chemical reactions that could turn "natural" salicylic acid (for instance) into "synthetic" salicylic acid. However, despite the outrage of those who believe "natural" raspberry ketone is superior to "artificial" raspberry ketone, and who are indignant at science's transforming "natural" remedies into identical (but more toxic) "poisonous chemicals", no such procedure has been shown to exist (nor is there any reason to believe it does, as the example of foxglove illustrates), and you will certainly not find it in any chemistry textbook. Proponents of the appeal to nature never explain, in detail, exactly how one is supposed to turn a "natural" molecule into an identical "synthetic" one. In other words, many are angered by a phenomenon they can't demonstrate or even describe!

An essential oil distillery for the distillation of sandalwood oil. Looks natural enough!

Many alternative medicine advocates will complain about "allopathy" using "chemicals" (meaning isolated substances) instead of plants, yet at the same time see no contradiction in using isolated active ingredients such as essential oils, glucosamine, glutamine, laetrile, chelation drugs, Tetrasil, Miracle Mineral Supplement, or any of the other countless non-herbal alternative medicines available, many of which are synthesized – like pharmaceuticals – and differ from conventional drugs only in that they are (usually) unapproved and unproven.[7]Grapefruit seed extract is criticized by some for consisting of unnatural chemicals, while others hail it as a natural remedy.[8][9][10] Some believers in the superiority of nature (some naturopaths, for instance) have no qualms using conventional pharmaceuticals, but arbitrarily classify some as being "good" and others as being "bad" for no apparent reason other than "I said so."[11][12][7] All this shows that not even believers in the appeal to nature agree on what the word "natural" is supposed to mean.[note 4]

Also, because of the Law of Conservation of Mass, no new mass nor energy can be created, so everything in the Universe is part of Nature and, one might say, "natural". Humans cannot create new energy nor mass, merely transform mass that already exists. In a very real sense, the word "natural" is meaningless, since anything not permitted by the laws of nature simply wouldn't exist.

But usually, the word "natural" is used by alternative practitioners to mean "not synthetic", that is, a substance not formed from chemical reactions caused by human intervention. This would indeed include drugs. During the infancy of chemistry, substances were taken from nature, and combined to create products (in the chemical sense). These substances, the result of combining entirely natural substances, would also be considered synthetic. But the water and carbon dioxide obtained from the reaction of sodium bicarbonate and vinegar or lemon juice would also be synthetic, according to this logic. If the water obtained from the reaction of vinegar and baking soda isn't synthetic, then what if that water were used for a further, second reaction? Would the resulting product be synthetic? At what point does a molecule cease to be "natural"?

All drugs and synthesized compounds have their origins in nature. If a human happened to combine the reactants, why should that make any difference? If the substances happened to be combined by some random force, would the product would be natural? Apparently, yes. Why? Why are some substances "synthetic" and therefore inferior, simply because a sentient being combined the reactants leading to its formation? If reactants are brought together by a human as opposed to by the random forces of nature or by some animal other than homo sapiens, why should that somehow modify the nature of the particles? Do humans have some negative aura that influences substances from a distance? Why is a product formed from the combination of reactants by a human more dangerous than one formed from the combination of reactants by random forces such as wind or gravity? And why doesn't this apply to homeopathy, which claims man-made homeopathic water is better than natural water?

There is a hidden premise that humans possess some taint that is transferred to anything they create, which is absent from anything created by absolutely any other species of living being in existence. Inherent in the premise is that humans are not part of nature. This is ridiculous in light of the fact that we are simply animals, who evolved in nature just as other animals did. The sole difference is our intelligence. And if the appealer to nature believes applying intelligence to the things we create instead of doing it randomly is bad, there's probably nothing you can say to them.

The appeal to nature is often accompanied by a comparison of the side effects of some drug, and those of some herbal supplement, with the former being more numerous and serious than the latter. It is argued that this is because of some property inherent to "natural" objects that makes them safer than non-natural ones. This comparison is flawed, however. The absurdity of this line of argument can be shown by replacing the herbal supplement in the comparison with one of the many available synthetic alternative remedies. Consider Tetrasil, a synthetically produced substance marketed in alternative medicine as a cure for various diseases, despite being unproven and unapproved by any regulatory agencies. Like conventional pharmaceuticals, it is a compound obtained by combining certain reactants (as opposed to being extracted directly from an existing natural source), yet Tetrasil products do not bear the threatening, long lists of possible side effects commonly associated with pharmaceuticals. Is this because unlike all other synthetic substances, Tetrasil only is exempt from the supposed "law of synthetic inferiority"? Or is it because there is a property specific to unstudied substances that makes them inherently safer than studied ones, due to which merely studying a substance causes it to be harmful? Not likely. A more reasonable explanation would be that Tetrasil, which (like many other artificial alternative medicines) has not undergone the study necessary for regulatory approval, probably does have side effects that are simply unknown due to lack of sufficient research, just as somenaturalremedies had serious side effects that were completely unknown for centuries or even millennia until they were subject to scientific study. One could just as well compare the apparent safety of Tetrasil to the proven toxicity of a plant like aconite and argue that this represents "proof" that synthetic substances are less harmful than natural ones.

In addition, comparing the side effect profiles of a given quantity of a herb with that of the same quantity of a drug derived from it is like comparing apples and oranges. A drug is a pure active ingredient, whereas a plant may contain hundreds of different chemicals, of which only a few may actually have medicinal effects. As Steven Novella noted, "The fact that individual chemicals are not purified and given in precise amounts does not mean they are not pharmacologically active chemicals – it just means that when taking an herbal remedy you are getting a mixture of many chemicals in unknown doses."[13] It would not be particularly surprising for a given quantity of a drug to be stronger (and hence have more or more severe side effects) than the same quantity of the plant it is derived from; the drug would contain more active ingredient per weight than the plant. Some plants may indeed, for this reason, be safer than their pharmaceutical derivatives, but this does not imply that they are also more (or even just as) effective, and this certainly could not be extended into a general rule applicable to all, or even most, plants. For example, it could by no means be said that foxglove is safe, and that digoxin is unsafe, just because foxglove is a plant and digoxin is not. The same goes for aconite and aconitine, tobacco and nicotine, and countless other plant/active compound pairs.[note 5]

To draw such a broad and far-reaching conclusion about the fundamental nature of matter not from scientific experiments conducted by (say) particle physicists, but this flimsy comparison, is absurd.

In addition, this comparison also ignores all the poisonous plants and substances found in nature and not sold on the supplement market. Supplements generally are safer than pharmaceuticals, but it is not necessary to resort to pseudo-chemistry to explain this.

(Besides, if such a "natural-synthetic" distinction did exist, it would mean all plants, and not just the ones on the market, would be safe; one could go into a forest and safely eat any plant matter one would find — as opposed to, say, dying in excruciating pain).

It need only be noted that in the 19th century and earlier, when no regulations were in place, traditional medicine used all sorts of "natural" and toxic remedies not available today in the markets of developed Western countries, such as belladonna (Atropa belladonna) cigarettes, lead, asbestos, comfrey, and tobacco, among others. Now, by contrast, these sorts of products have pretty much been banned, so, in general, only the harmless (and usually, though not always, useless) ones remain. (For examples of traditional natural remedies with mild-to-serious side-effects, see RationalWiki's list of medicinal plants and Mark Twain's essay A Majestic Literary Fossil.)

Indeed, in regions where traditional medicine is still going strong, and regulation of such practices are lax, many toxic remedies are used. (And by traditional medicine is meant real traditional medicine, not the emasculated, modern Western invention that is naturopathy, which only uses products that have not been banned.) Lead[14][15] and birthwort, for instance, are used as folk remedies in many parts of the world.

In a world where all medicines were "natural" and unregulated, the medical profession's arsenal of herbs and salves would, just as before the 19th century, and just as in many parts of the world today, undoubtedly include many not particularly safe ones. The difference between the poisonous medicines of today and those of yore is, of course, that the former have been tested for their efficacy.

Another point to be made is that drugs are tested very thoroughly, by means of trials involving very large numbers of people and extending over long periods of time, and there are reporting systems in place to detect any possible (and potentially very rare) adverse effects they may have, after they have been launched on the market, leading to the well known lengthy lists of side effects. Side effects for herbal products, as well as non-herbal supplements, on the other hand, are not as well monitored or recorded, meaning that a herbal product could indeed have side effects (serious or otherwise) that, because of lack of regulation or research, have simply not been discovered. (Under-reporting of adverse effects is a prevalent issue for both drugs[16] and herbal supplements,[17] but likely more so in the latter.[18][19]) As Steven Novella noted in an article on birthwort:[13]

“”Common use may be enough to detect immediate or obvious effects, but not increased risk of developing disease over time. That requires careful epidemiology or specific clinical studies. We know about the risks of prescription drugs only because they are studied, and then tracked once they are on the market. Without similar study and tracking there is simply no way to know about the risks of herbal products.

Indeed, before the advent of evidence-based medicine, many harmful natural remedies — such as birthwort (Aristolochia spp.), asbestos, and comfrey — were, and in some places still are, used as medicines without their harms being known at all (anecdotal evidence and personal observation being very bad at detecting long-term side effects). This is in contrast to modern pre- and post-market side effect detection systems that involve many thousands of people, and that can discover possible toxic events that are extremely rare. For instance, the frequency of some side effects can be as low as 1 per 100,000 patients.[20][21] Such rare side effects could never be detected with the experience- and anecdote-reliant approach favored by alternative practitioners. (Indeed, if an alternative practitioner did have a patient experience such an adverse effect, they would likely assume that it cannot possibly be due to a "safe, natural remedy" like asbestos, and that it must be because of something else, like the clearly man-made substancegluten or the ever-ubiquitous "toxins".) Not to mention that some side effects only occur a very long time after exposure. As epidemiologist Geoffrey Kabat noted:[22]

“”What is essential to realize is that the effects of Aristolochia [birthwort] were identified only thanks to the large cluster of cases of kidney failure occurring in young women who had attended the same spa. It is much more likely that isolated cases will go unnoticed, as happened with ephedra, and it could take years to identify a common cause.

People failed to recognize the nephrotoxic effects of Aristolochia in spite of its use in many cultures worldwide over thousands of years. In an interview, Grollman explained why: “The reason, of course, is quite simple. It’s painless, and the damage happens much later, so you don’t put together the fact that you took this medicine and four years later, you have kidney failure. It’s been part of Ayurvedic, European, Chinese, and South American medicine for centuries. All of the great civilizations have used it. And not one reported its toxicity until the Belgians did 20 years ago. There are certain things that tradition can’t tell you.”

If alternative medicines were studied as extensively as pharmaceuticals are now, previously-unknown side effects of many more natural remedies would undoubtedly be discovered.

It is also claimed that herbal medicine "is food, so it must be safe." Of course, just because some plants are food does not mean they all are. Many, if not most, of the herbs used in herbal supplements sold for therapeutic purposes have no nutritional value, and are taken solely for their pharmacological effects on the body. To quote Steven Novella:[13]

“”With food and food ingredients the FDA does not require evidence of safety if the ingredient is generally recognized as safe. This might make sense when referring to foods that have been eaten by humans for a long time. Although the logic is still dubious, it’s just practical – the FDA could not take upon itself the task of proving that every food eaten by humans has no significant negative health consequences. It is more a recognition of practicality than reality. [...] Herbal remedies are drugs, plain and simple. They contain chemicals that are ingested on a regular basis for their pharmacological effects. The fact that they derive from plants is irrelevant.

Not to mention that many natural foods are quite unhealthy and can have detrimental effects on the human body. Ironically, many vegetarians and vegans believe strongly that natural things can't harm you, and simultaneously that consuming meat and/or animal products will kill you.

This box jellyfish is all-natural and therefore touching its tentacles is good for you and will not send you into horrible pain and then death in a few minutes a state of reconnection with the earth-spirit!

Examples include cyanide, a deadly yet natural poison, or smallpox; while fertilisers, many modern medicines, hygiene, and semiconductor-grade silicon do not occur naturally, they have great benefit to humans individually and in societies.

Appeals to nature form the bread and butter for all nature woo: my quack remedy is from all-natural goats, and therefore good for you. For example, the anti-vaccine crowd may state that humans get immunity to diseases without vaccines, and thus conclude that vaccines are unnatural and ought not be used on children.

Cloning is considered unnatural, if you ignore the existence of identical twins, and you ignore that no one has actually cloned a human and "vat grown humans" are mostly science fiction at this point.

In the U.S., the food industry, aided by the Food and Drug Administration's lack of regulation on the term, has also capitalized on the "all natural" craze. For instance, we have "all-natural" Sprite, which uses high-fructose corn syrup, produced by a centrifuge. However, this still raises the question as to when something becomes or ceases to be 'natural.' Using the above example, all of the materials used to make HFCS do in fact come from raw materials. Putting a line in the sand as to using a centrifuge is arbitrary at best.

Few people take this fallacy to the logical extreme, such as livinglike acaveman, avoiding indoors and staying outside like a dirty animal (in the pejorative sense, not the "belonging to kingdom Metazoa" sense) while staring at the Sun, with no technology or human advancements of any kind. Some hard greens have advocated it, although very few of them decide to practice as they preach and close down their websites to "live with nature" (or if they have but can't to tell us). Most try to weakly argue that they "use technology against itself" or some such, and tend to ignore that forgoing all "unnatural" innovations such as farming and clothing would limit humanity to a population of maybe a few million in the tropics; few are volunteering to be among those that die off.

Quite a few foods are actually naturally toxic, even in unadulterated or uncontaminated form. This is because there is a war on for survival, and all plants contain natural pesticides that they use to deter herbivory. Plant domestication has generally reduced the natural pesticide content of foodstuffs, but it hasn't fully eliminated it (and not all of it needs to go away, per se, or we'd have vulnerable crops instead). Some animals are also toxic to eat, including some fish, birds, and amphibians. In this section are foods that are sometimes toxic to consume, not foods that merely contain toxins (as almost all plant foods contain toxins naturally). See also "Naturally Occurring Food Toxins" for a review of hazardous foods.[23]

Ackee (Blighia sapida, Sapindaceae family) is a popular Jamaican fruit that was originally imported from Africa, where it is also eaten. It causes Jamaican vomiting sickness because of the natural presence of hypoglycin A in the fruits. When the fruits are fully ripe, hypoglycin A is present at only <0.1 ppm but unripe fruits can contain 1000 ppm, which can be lethal.[24]

Aside from being a magical fruit, many varieties of beans are actually toxic and contain high amounts of phytohaemagglutinin. Luckily, this toxin breaks down via boiling.

Favism is a disease caused by among other things, consumption of fava beans (Vicia faba). The disease only affects people with a specific genetic predisposition that is common in people of Mediterranean and African origin. Symptoms include jaundice, hemolytic crises, diabetic ketoacidosis, and acute kidney failure.

Cassava (Manihot esculenta), also known as yuca or manioc is a starchy root that is a dietary staple in some parts of the world. It is also naturally high in cyanide. When not properly prepared, it has caused intoxication, goiters, and even ataxia, partial paralysis, or death.[25] The bitterer varieties (higher in cyanide) are often preferred by farmers because they are better pest deterrents.[26]

Puffer fish (family Tetraodontidae) are considered a delicacy in Japan and is known as fugu (河豚). Puffer fish naturally contain tetrodotoxin, which may originate from their intestinal bacteria.[30]Fugu chefs are specially trained to remove enough parts of the fish to prevent death but to sometimes induce euphoric feelings from intoxication, but deaths still occur on occasion.[31]

Escolar (Lepidocybium flavobrunneum) and oilfish (Ruvettus pretiosus) (both in family Gempylidae) are high in oil content, but are also high in indigestible wax esters which can cause oily diarrhea, nausea, headache, and vomiting.[32] Italy and Japan have banned the sale of these two fish, and other countries have put restrictions on their sale.[33]

Lychee (Litchi chinensis, Sapindaceae family) is native to China and is mainly grown in India and China. Outbreaks of noninflammatory encephalopathy in India and Vietnam have been linked to consumption of lychee, with symptoms similar to Jamaican vomiting sickness.[34][35] Lychee sickness is also due to the presence of hypoglycin as well as a similar toxin, methylenecyclopropyl glycine, in the fruit.[35]

There are many species of mushrooms, with widely ranging levels of toxicity. They range from the almost always fatal (not food, but sometimes mistaken for food) to the sometimes sickening (wild food) to the domesticated (e.g., the common mushroom Agaricus bisporus). Some wild species only sicken some people, e.g., A. hondensis,[36] whereas others are often deadly even though they are delicious (Amanita phalloides).[37]

The International Agency for Research on Cancer (IARC) regularly evaluates the evidence for whether various agents (chemicals, activities and exposure situations) for whether the agents are likely to be human carcinogens. The highest level of evidence, Group 1, are regarded as definitively "Carcinogenic to humans", usually based upon strong epidemiological evidence but also with supporting evidence from animal and mechanistic studies. As of December 2016, there have been 116 evaluations for Group 1 carcinogens.[39] Of these 116, 67 (58%) could be regarded as being from naturally-occurring chemicals, activities, or exposure situations.[40]

This is an imperfect count of natural carcinogens, but it nonetheless shows that natural is not inherently "good", and also that synthetic is not inherently "bad". The latter is the case because there are several synthetic cancer treatment drugs, which are effective in treating cancer but also carry a usually smaller risk for causing cancer. There is some redundancy in the table, e.g., there are several types of radiation exposures that have separate evaluations even though the mechanism of carcinogenesis is basically the same, which could be considered a type of double counting. The question of what is and is not natural is not always clear-cut, e.g., tanning beds seem synthetic but the mechanism of carcinogenesis is the same as that of natural Sun exposure.

Creationists often appeal to natural selection ("survival of the fittest"), as part of their continuing campaign of anti-evolutionary propaganda. In nature the weakest (least fit) die, so the naturalistic fallacy says that we should dismantle welfare states and withhold charity and health care, to leave poor and ill people to die, or even to exterminate the weak. This ignores Darwin's actual definition of "fit"; not the strongest but the most adaptable and responsive to change, meaning that "Darwinism" would encourage social safety nets and disaster relief.

Genetically modified foods are often decried as unnatural. (A more "sophisticated" version of this argument mentions something about "playing God" or a "laboratory".) This of course ignores that farming itself is unnatural, let alone traditional breeding methods and domestication. An analogy can be made here: pharmacology's basis is about purifying compounds, while genetic engineering is about isolating genetic traits. Both of them steer clear of the undesirable gunk that comes from natural processes.

Inevitably, whenever someone does something involving living things, someone else will call them out for "playing God". It's unclear why anything short of creating universes and tinkering with their inhabitants amounts to "playing God". It's also unknown why "playing God" (a supposedly all-benevolent creator of everything that is good) is a bad thing. Besides, as The Onion notes:[42]

“”Modern scientists have long since surpassed the power and strength accorded to your feeble God.

Socialism and associated policy proposals are frequently held to be contrary to human nature while social Darwinist ideologies and policy proposals are held to be natural and pure. In doing this, the right avoids discussing the pros and cons of particular policies in favor of a philosophical debate over "the nature of mankind."

Appeals to nature often take the form of "It's human nature" or, in more modern usage, "It's the Internet" in order to excuse, justify or downplay the bad behavior of other people, protecting their actions from criticism. Examples:

People eventually die anyway, so why bother fighting any disease?

It's an inevitable part of human nature that the stronger and more civilized take advantage of the weaker and more savage, so why fight slavery?

↑This is, of course, why solar radiation is not at all dangerous to astronauts, and radiation shielding for spacecraft is completely unnecessary.

↑Plants have variable amounts of chemicals, which is why evidence-based medicine uses pure active ingredients rather than plants; the amount of active ingredient varies (sometimes wildly) from plant to plant (this is why potatoes can sometimes cause solanine poisoning). Drugs, on the other hand, are precisely dosed. In the example of foxglove, for instance, this means that a given quantity of one individual foxglove plant may contain a beneficial amount of digoxin, while the same quantity from another individual may be toxic:

Foxglove is no longer used as a heart medicine because the therapeutic dose and the lethal dose are very close. Seasonal variations in the level of cardiac glycosides in the plant make the safe dose impossible to estimate except by an experienced physician and prescriber of the herb who monitors the patient on an hourly basis for signs of overdose. Few living doctors and herbalists can safely use digitalis as a plant extract. Specific standardized doses of pharmaceutical digoxin are used instead.

↑The word "natural" is also frequently used to refer to techniques such as chiropractic and acupuncture to imply that their mainstream equivalent, physiotherapy, somehow isn't – but these therapies are all essentially physical manipulation; chiropractic and acupuncture are not somehow more natural just because their users said so.

↑Incidentally, in Christopher Buckley's novel Thank You for Smoking, the protagonist, a tobacco lobbyist, makes the claim that it is not the nicotine in tobacco that is harmful, but the nicotine found in nicotine patches. This is essentially not all that different from the claims made by many advocates of "natural" remedies.